<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      // 创建实例的优先级 render最高
      const app = new Vue({
        // el: '#demo',
        template: '<div>template</div>',
        // render(h) {
        //   return h('div', 'render')
        // },
        data: { foo: 'foo' },
      }).$mount('demo')
      // 源码
      if (!options.render) {
        if (tempalte) {
          //...
        } else if (el) {
          template = getOuterHTML(el)
        }
      }
    </script>
  </body>
</html>
